Power machines, particularly walk-behind power machines, often employ an operator control handle or bail to actively control a component of the power machine. In addition to providing a means of controlling the power machine, the bail is often employed to enforce operator presence for safety reasons. For example, it is a requirement for walk-behind power mowing machines to have a “dead man” control, which generally includes a spring-biased bail which can be grasped by the operator during normal operation of the machine to enable the motor of the machine. If the bail is thereafter released, the machine action is rapidly terminated for reasons of safety. In the case of a “dead man” control on a lawn mower, the engine and the rotating blade are both rapidly stopped when the operator releases the bail.
More recently, blade brake clutch (BBC) control apparatuses have been employed to enforce operator presence while using lawn mowers. A BBC control allows the rotating cutting blade to be stopped and engine to remain enabled when the operator releases the bail controlling the BBC. When the bail is moved to the engaged position, the BBC control activates the clutch whereby the cutting blade is engaged. When the bail is released by the operator, the BBC control disengages the clutch and the brake mechanism is applied to stop rotation of the blade. This action prevents the blade from free spinning to a stop, in which an injury could occur to the user while the blade slows from an extremely high velocity of rotation.
It is now a requirement that bails on walk-behind lawn mowers designed to enforcing operator presence comprise a two-step apparatus such that a user must perform a two-step process before the blade can be engaged for rotation. Thus, a two-step bail apparatus for a lawn mower would provide for operator control of the mowing machine as well as conform to safety regulations.